Process of nitrating regenerated cellulose films or paper



May 19, 1925. 1,538,294

V L. LUMIERE PROCESS OF NITRATING REGENERATED CELLULOSE FILMS OR PAPER Filed April 4, 1924 .In/venfww' Patented 19, 1925.

UNITED STATES FICE.

PATENT or LOUIS LUMIERE, or LYON, FRANCE, ASSIGNOR T s ocrE'rE ANONYME UNION PHO- 'TOGRAIHIQUE INDUSTRIELLE, ETABLISSEMENTS LUMIERE.&, JOUGLA nnonrs,"

0F LYON, FRANCE.

PROCESS OF NITBATING REGENERATED CETILULOSE FILMS OR PAPER.

* Application filed A ril Toall whom it may'concewt:

Be it known that I, LoUIs LUMIERE, residing at Lyon, France, a citizen of the'French Republic, have invented a certain new and useful Process of Nitrating Begenerated Cellulose Films or Paper, of which the fol lowing is a specification.

Films or ellicles of regenerated cellulose known as cellophane are employed for various uses but this kind of film cannot be used in photography for the principalappreciably able for use in photographicprocesses and having the same characteristics. as those .manufactured by the means known at present. This process of nitration is essentially characterized by the fac-t'that the cellophane film is treated successively with'nitric acid and sulphuric acid, whereas in the known processes the nitration is effected by "nitric acid and the sulphuric acid mixed together.

In the improved process either successive baths ofnitric and surphuric acid are employed through which the cellophane film passes or the film is treated with successive afiusions of these two acids.

The attached diagrammatic drawing llwhich either method can be used. v

The cellophane film ppasses'in the first place into .a bath of nitric acid at 40 Baum for example, contained in a tank ,b,.lthen over a conveyor roller h and then passes into a bath of sulphuric, acid at for example 66 Banm contained in a second tank 0 situated adjacent the first. On leaving the latter tank the film is washed by passing it.

through {one or more tanks d 'containing pure water and then if required through alkaline water and finally again throu h pure-water. Instead of being used, in tie form of baths the nitric and, sulphuric acids as well as the washing liquids can be dis- .tributed regularly on thetwo faces of the cellophane film by perforated tubes t, t which respectively spray the two acids-and the washing waters through a multitude of jets on to the film. The acids fall to the lustrates an example of an installation, in.

4, 1924. Serial no. 704,254.

bottoms of the recovered. If necessary, drying rollers 9 could be arranged in combination with the conveyor roller h, 2' for the purpose of removing the telxcess of acid from the film passing between em.

henit is required to prolong the duration of contact of the cellophane film either with the nitric acidv or with the sulphuric acid several successive tanks or distributors could be used for the acid. I

The regenerated cellulose film is impregnated firstly with nitric acid without undergoing any appreciable transformation and it tanks b and 0 and are finally is only the dehydrating action of the sul--" phuric acid which causes the nitration. Consequently the excess of nitric acid in the first bath remains unaltered and can be cont nued to be used without loss until exhaustion. Only the sulphuric acid requires regenerating, which can be easily eflected.

The process is consequently very economical since it provides for the manufacture of nitro-cellulose films Without the necessity of using costly solvents as the manufacture hitherto ado ted requires.

The film nished, washed, and dried may be found to have an-opalescent'appearance which can be easily removed by passing it through a chamber containing vapours of a solvent of nitro-cellulose, acetone for example.

" Finally it is possible to' obtain thick pellicles by successively sticking together severalfilms by means of acetone, acetate amil or any other suitable solvent, 'the latter may also contain a dissolved plasticitant, camphor for example. I s

The process can be employed for the-nitration of paper in view of its utilization in the manufacture of celluloid and collodions. The concentrations of the nitric and sulphuric acids can vary within a certain limit according to the results to be obtained.

What I claim as my invention anddesire to secure by Letters Patent of the United States is K 1. Process of nitrating regenerated cellulose films consisting in impregnating the film with nitric acid, treating the film thus impregnated with sulphuric acid and then washing and drying the film. 2. Process of nitrating regenerated cellulose films consisting in impregnating the film with nitric acid, treating the film thus impregnated with sulphuric acid washing and drying the film and then passing it through a chamber containing vapours of a solvent of nitro-cellulose.

3. Process of nitrating regenerated cellulose films consisting in subjecting the film to successive and alternate washings ofnitric and sulphuric acids, then washing the film in water and drying same.

4. Process of nitrating regenerated cellulose films consisting in subjecting the film to In witness whereof I have signed this 20 specification.

LOUIS LUMIERE.

Witnesses: I 7

CYRUS B. FoLLMER, L. Esom. 

